Blue triphenylmethane dyestuff.



' To all whom it may concern:

UNITED STATES PATENT OFFICE.

MAX WEILER, 0F ELBERFELD, GERMANY, ASSIGNOB TO FARBENFABRIKEN VOBM. FRIEDB. BAYER & GO OF ELBERFELI), GERMANY, A CORPORATION OF GERMANY.

1,004,610. No Drawing.

Specification 015 Letters Patent Patented Oct. 3,1911.

Be it known that I, Max Wanna doctor of philosophy, chemist, citizen of the German Empire, residing at Elberfeld, Germany; have invented new and useful Improvements in Blue Dyestulf, of which the following is a specification.

The present invention relates to the manufacture and production of a new triphenylmethane dye, which is distinguished by a high fasteness to alkali and to millmg.

The process for its production consists in condensing -dichloro-meta-oxy-benzaldehyde with ortho-cresotinic acid and oxidizing the leuco compound.

.In order to illustrate the new process more fully the following example is given,

the parts being by weight :-17.5 parts of more be proved to be present in the mixture.

The melt is poured into 600 parts of ice water and the precipitate is filtered oil. The

demo acid thus obtained can be further purifled by dissolving it in soda and separating it againwith an acid. The product thus produced is insoluble in .water, easily soluble in chloroform and in acetone. The acetone solution assumes an intense blue-violet color by heating it with bichromate and sulfuric acid. Ferric chlorid gives in an alcoholic solution a pure blue tint. For oxidation the leuco acid is dissolved in strong sulfuric acid and the solution is stirred with the addition of-the necessary quantity of nitrite at 30-35 C. until the quantity of the dyestuil produced does no longer increase. The melt 1s poured on ice. The dyestufi thus separated is after being dried and pulverized a scarlet-red powder. It is slightly soluble in hot water with a scarlet-red color and solu-' ble in caustic soda lye with an intense violetcolor and has probably the formula:

Application filed February 7, 1911. Serial No. 607,174.

at the 2.6, 2.4, or. 4.6 position.

It can also be dyed on wool which has been previously treated with chrome or in one bath with sulfuric acid and bichromate.

Its chromed shades are blue.

I claim The herein described new dye having probably the following formula:

CH3 CH3 4 in which formula two atoms of chlorin are substituted in the oxybenzene nucleus, which is after being dried and pulverized a scarlet-red powder soluble in hot water with a scarlet-red color, soluble in caustic soda lye with a violet color; dyeing chromed wool pure blue shades, substantially as described. y

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

MAX WEILER. [L.' s.] \Vitnesses:

CHAs. J. \Vmoirr, WALTER VONNEGUT. 

